Summary of Significant Accounting Policies (Policies)	6 Months Ended
Jun. 30, 2019
Accounting Policies [Abstract]
Revenue Recognition	Revenue Recognition Revenue is recognized when a customer obtains control of promised goods or services, in an amount that reflects the consideration which the entity expects to receive in exchange for those goods or services. To determine revenue recognition for arrangements that an entity determines are within the scope of ASC 606, Revenue from Contracts with Customers (“ASC 606”), the Company performs the following five steps: (i) identify the contract(s) with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when (or as) the entity satisfies a performance obligation. The Company only applies the five-step model to contracts when it is probable that the entity will collect the consideration it is entitled to in exchange for the goods or services it transfers to the customer. At contract inception, once the contract is determined to be within the scope of ASC 606, the Company assesses the goods or services promised within each contract, determines those that are performance obligations and assesses whether each promised good or service is distinct. The Company then recognizes as revenue the amount of the transaction price that is allocated to the respective performance obligation when (or as) the performance obligation is satisfied. Sales, value add, and other taxes collected on behalf of third parties are excluded from revenue. Product sales, net — The Company began selling YUTIQ and DEXYCU in February and March 2019, respectively. The Company is currently selling YUTIQ and DEXYCU in the U.S. through a single third-party logistics provider (the “3PL”), which takes title to the goods. The 3PL distributes the products through a limited number of specialty distributors and specialty pharmacies (collectively the “Distributors”), with whom the Company has entered into formal agreements, for delivery to physician practices for YUTIQ and to hospital outpatient departments and ambulatory surgical centers for DEXYCU. The Company recognizes revenue on sales of products when the 3PL obtains control of the products, which occurs at a point in time, typically upon delivery. The Company expects to enter into arrangements with healthcare providers and payors that provide for government mandated and/or privately negotiated rebates, chargebacks, and discounts with respect to the purchase of the Company’s products. Reserves for variable consideration — Product sales are recorded at the wholesale acquisition costs, net of applicable reserves for variable consideration. Components of variable consideration include trade discounts and allowances, provider chargebacks and discounts, payor rebates, product returns, and other allowances that are offered within contracts between the Company and its Distributors, payors, and other contracted purchasers relating to the Company’s product sales. These reserves, as detailed below, are based on the amounts earned, or to be claimed on the related sales, and are classified either as reductions of accounts receivable or a current liability, depending on how the amount is to be settled. Overall, these reserves reflect the Company’s best estimates of the amount of consideration to which it is entitled based on the terms of the respective underlying contracts. Actual amounts of consideration ultimately received may differ from our estimates. If actual results in the future vary from our estimates, the Company adjusts these estimates, which would affect product revenue and earnings in the period such variances become known. Distribution fees — The Company compensates its Distributors for services explicitly stated in the Company’s contracts and are recorded as a reduction of revenue in the period the related product sale is recognized. Provider chargebacks and discounts — Chargebacks are discounts that represent the estimated obligations resulting from contractual commitments to sell products at prices lower than the list prices charged to our Distributors. These Distributors charge us for the difference between what they pay for the product and our contracted selling price. These reserves are established in the same period that the related revenue is recognized, resulting in a reduction of product revenue and the establishment of a current liability. Reserves for chargebacks consist of amounts that the Company expects to pay for units that remain in the distribution channel inventories at each reporting period-end that the Company expects will be sold under a contracted selling price, and chargebacks that Distributors have claimed, but for which the Company has not yet settled. Government rebates — The Company is subject to discount obligations under state Medicaid programs and Medicare. These reserves are recorded in the same period the related revenue is recognized, resulting in a reduction of product revenue and the establishment of a current liability which is included in accrued expenses and other current liabilities on the condensed consolidated balance sheets. The Company’s liability for these rebates consists of invoices received for claims from prior quarters that have not been paid or for which an invoice has not yet been received, estimates of claims for the current quarter, and estimated future claims that will be made for product that has been recognized as revenue, but which remains in the distribution channel inventories at the end of each reporting period. Payor rebates — The Company expects to contract with certain private payor organizations, primarily insurance companies, for the payment of rebates with respect to utilization of its products. The Company estimates these rebates and records such estimates in the same period the related revenue is recognized, resulting in a reduction of product revenue and the establishment of a current liability. Co-Payment assistance — The Company offers co-payment assistance to commercially insured patients meeting certain eligibility requirements. The calculation of the accrual for co-pay assistance is based on an estimate of claims and the cost per claim that the Company expects to receive associated with product that has been recognized as revenue. Product returns — The Company generally offers a limited right of return based on its returned goods policy, which includes damaged product and remaining shelf life. The Company estimates the amount of its product sales that may be returned and records this estimate as a reduction of revenue in the period the related product revenue is recognized, as well as reductions to trade receivables, net on the condensed consolidated balance sheets. Cost of sales, excluding amortization of acquired intangible assets — Cost of sales, excluding amortization of acquired intangible assets, consist of costs associated with the manufacture of YUTIQ and DEXYCU, certain period costs, product shipping and, as applicable, royalty expense. The inventory costs for YUTIQ include purchases of various components, the active pharmaceutical ingredient (“API”) and internal labor and overhead for the product manufactured in the Company’s Watertown, MA facility. The inventory costs for DEXYCU include purchased components, the API and third-party manufacturing and assembly. Capitalization of inventory costs begins after FDA approval of the product. Prior thereto, inventory costs of products and product candidates are recorded as research and development expense, even if this inventory may later be sold as commercial product.

Summary of Significant Accounting Policies (Policies)

6 Months Ended

Jun. 30, 2019

Revenue is recognized when a customer obtains control of promised goods or services, in an amount that reflects the consideration which the entity expects to receive in exchange for those goods or services. To determine revenue recognition for arrangements that an entity determines are within the scope of ASC 606, Revenue from Contracts with Customers (“ASC 606”), the Company performs the following five steps: (i) identify the contract(s) with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when (or as) the entity satisfies a performance obligation. The Company only applies the five-step model to contracts when it is probable that the entity will collect the consideration it is entitled to in exchange for the goods or services it transfers to the customer. At contract inception, once the contract is determined to be within the scope of ASC 606, the Company assesses the goods or services promised within each contract, determines those that are performance obligations and assesses whether each promised good or service is distinct. The Company then recognizes as revenue the amount of the transaction price that is allocated to the respective performance obligation when (or as) the performance obligation is satisfied. Sales, value add, and other taxes collected on behalf of third parties are excluded from revenue.

Product sales, net — The Company began selling YUTIQ and DEXYCU in February and March 2019, respectively. The Company is currently selling YUTIQ and DEXYCU in the U.S. through a single third-party logistics provider (the “3PL”), which takes title to the goods. The 3PL distributes the products through a limited number of specialty distributors and specialty pharmacies (collectively the “Distributors”), with whom the Company has entered into formal agreements, for delivery to physician practices for YUTIQ and to hospital outpatient departments and ambulatory surgical centers for DEXYCU. The Company recognizes revenue on sales of products when the 3PL obtains control of the products, which occurs at a point in time, typically upon delivery. The Company expects to enter into arrangements with healthcare providers and payors that provide for government mandated and/or privately negotiated rebates, chargebacks, and discounts with respect to the purchase of the Company’s products.

Reserves for variable consideration — Product sales are recorded at the wholesale acquisition costs, net of applicable reserves for variable consideration. Components of variable consideration include trade discounts and allowances, provider chargebacks and discounts, payor rebates, product returns, and other allowances that are offered within contracts between the Company and its Distributors, payors, and other contracted purchasers relating to the Company’s product sales. These reserves, as detailed below, are based on the amounts earned, or to be claimed on the related sales, and are classified either as reductions of accounts receivable or a current liability, depending on how the amount is to be settled. Overall, these reserves reflect the Company’s best estimates of the amount of consideration to which it is entitled based on the terms of the respective underlying contracts. Actual amounts of consideration ultimately received may differ from our estimates. If actual results in the future vary from our estimates, the Company adjusts these estimates, which would affect product revenue and earnings in the period such variances become known.

Distribution fees — The Company compensates its Distributors for services explicitly stated in the Company’s contracts and are recorded as a reduction of revenue in the period the related product sale is recognized.

Provider chargebacks and discounts — Chargebacks are discounts that represent the estimated obligations resulting from contractual commitments to sell products at prices lower than the list prices charged to our Distributors. These Distributors charge us for the difference between what they pay for the product and our contracted selling price. These reserves are established in the same period that the related revenue is recognized, resulting in a reduction of product revenue and the establishment of a current liability. Reserves for chargebacks consist of amounts that the Company expects to pay for units that remain in the distribution channel inventories at each reporting period-end that the Company expects will be sold under a contracted selling price, and chargebacks that Distributors have claimed, but for which the Company has not yet settled.

Government rebates — The Company is subject to discount obligations under state Medicaid programs and Medicare. These reserves are recorded in the same period the related revenue is recognized, resulting in a reduction of product revenue and the establishment of a current liability which is included in accrued expenses and other current liabilities on the condensed consolidated balance sheets. The Company’s liability for these rebates consists of invoices received for claims from prior quarters that have not been paid or for which an invoice has not yet been received, estimates of claims for the current quarter, and estimated future claims that will be made for product that has been recognized as revenue, but which remains in the distribution channel inventories at the end of each reporting period.

Payor rebates — The Company expects to contract with certain private payor organizations, primarily insurance companies, for the payment of rebates with respect to utilization of its products. The Company estimates these rebates and records such estimates in the same period the related revenue is recognized, resulting in a reduction of product revenue and the establishment of a current liability.

Co-Payment assistance — The Company offers co-payment assistance to commercially insured patients meeting certain eligibility requirements. The calculation of the accrual for co-pay assistance is based on an estimate of claims and the cost per claim that the Company expects to receive associated with product that has been recognized as revenue.

Product returns — The Company generally offers a limited right of return based on its returned goods policy, which includes damaged product and remaining shelf life. The Company estimates the amount of its product sales that may be returned and records this estimate as a reduction of revenue in the period the related product revenue is recognized, as well as reductions to trade receivables, net on the condensed consolidated balance sheets.

Cost of sales, excluding amortization of acquired intangible assets — Cost of sales, excluding amortization of acquired intangible assets, consist of costs associated with the manufacture of YUTIQ and DEXYCU, certain period costs, product shipping and, as applicable, royalty expense. The inventory costs for YUTIQ include purchases of various components, the active pharmaceutical ingredient (“API”) and internal labor and overhead for the product manufactured in the Company’s Watertown, MA facility. The inventory costs for DEXYCU include purchased components, the API and third-party manufacturing and assembly. Capitalization of inventory costs begins after FDA approval of the product. Prior thereto, inventory costs of products and product candidates are recorded as research and development expense, even if this inventory may later be sold as commercial product.